Can you guess the position of all the planets in our solar system 5 billion years from now? To answer this question, in 2009, two scientists conducted an experiment that shocked the entire scientific community. In this experiment, they ran over 2,000 computer simulations. These simulations were based on a simple principle: they reset all planets to their current positions and then projected the state of the solar system 5 billion years into the future. However, the scientists added a small twist to each simulation—they reduced the distance between the Sun and Mercury by just 1 millimeter each time. Now, you might be wondering, what difference could such a small change make? But what the scientists observed truly stunned them.

The scientists found that In 1% of these 2,000 simulations, Mercury’s orbit became so unstable that it either collided with the Sun or Venus. Even more alarming, in these simulations, Mercury destabilized the entire solar system, causing all planets to either collide with each other or with the Sun, completely erasing the existence of our solar system. And this all happened just because the scientists moved Mercury’s orbit 1 millimeter closer to the Sun. These simulations raised a major concern among scientists because they suggested that our solar system might not be as stable as it appears. This phenomenon is known as the “Three-Body Problem,” a puzzle that scientists have been trying to solve for over 300 years but have yet to fully resolve.

Let’s first understand what the Three-Body Problem actually is. Imagine a star system where there are three or more bodies, like stars, planets, or moons, all bound by each other’s gravitational force. Predicting the exact future positions of these three bodies becomes extremely difficult. The challenge here is that when only two bodies are involved, scientists can easily determine their future positions and orbits. But as soon as a third body is introduced, things become complex. These three bodies exert gravitational forces on each other, making it nearly impossible to accurately predict their future positions. The complexity of this problem is such that even a slight change in the initial position or speed of these bodies can cause the entire system’s outcome to become completely unpredictable. This makes it uncertain to forecast the system’s future. Scientists have been attempting to solve this problem for decades because resolving it could help them better understand gravitational interactions among celestial bodies and planetary events.

The first study on the Three-Body Problem was conducted by Isaac Newton in the 17th century. Newton described this problem in Principia, a significant book published in 1687, considered one of the most influential works in the history of physics. Using Newton’s Universal Law of Gravity formula, scientists have been able to predict the future of two-body systems with ease for centuries. But when a third body is added, the problem becomes highly unsolvable. In the 19th century, Henri Poincaré tried to solve the Three-Body Problem but eventually concluded that there is no exact solution. Poincaré stated that even small changes could lead to significant and unpredictable outcomes, but he also mentioned that in certain situations, solutions could be reached, such as when the three bodies orbit in certain shapes or patterns. But do such problems truly exist in our real universe? The answer is yes. Complex systems where three or more bodies are bound by each other’s gravity are found everywhere in the universe. A prime example of this is the Alpha Centauri star system, located four light-years away from us. This system contains three stars: Alpha Centauri A, Alpha Centauri B, and Proxima Centauri, all bound by each other’s gravity. Due to the nearly equal gravitational pull of Alpha Centauri A and Alpha Centauri B, these two stars orbit in a specific pattern.

But why do scientists want to solve this? Would they gain any benefits, or are they just solving it out of curiosity? Solving the Three-Body Problem would allow scientists to gain a deeper understanding of gravity. It would give them the opportunity to understand how gravity functions when multiple massive bodies are present in a system. Resolving this problem would also help better understand the interactions between galaxies. It would benefit space research, such as determining safe paths for space satellites or telescopes and protecting them from asteroid collisions. But you’ll be glad to hear that scientists say our solar system will remain in a stable position for millions of years to come.

The Three-Body Problem is not just a science puzzle but also a symbol of the deep and infinite possibilities of our universe. It shows us that no matter how much we understand science and math, uncovering every mystery of the universe might be impossible for humans. What do you think? Will there ever be a solution to the Three-Body Problem? Will science ever be able to fully understand this problem? What are your thoughts on this? Be sure to comment below. Thank you for reading my article till the end. If you enjoyed this article, please consider liking, sharing, and following for more science-related content.

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Acknowledgments

This article would not have been possible without the guidance, support, and collaboration of numerous individuals and institutions, to whom I owe my deepest gratitude. First and foremost, I would like to extend my sincere thanks to my academic mentors and advisors, whose expertise and insights have been instrumental in shaping this work. I am particularly grateful to Dr. Sarah Thompson at the University of Cambridge, whose profound knowledge in celestial mechanics and gravitational theory provided invaluable guidance throughout the research process. Your patience and encouragement have been a source of motivation, and your critical feedback has greatly enhanced the clarity and rigor of this article. Special thanks are also due to the faculty at the Institute for Theoretical Physics, particularly Prof. James Lin, whose seminars on chaos theory and computational physics sparked my initial curiosity and laid the groundwork for my exploration of the Three-Body Problem. Your insights on the historical and theoretical framework surrounding this topic have been vital to the depth of analysis presented here. I am indebted to the dedicated team of researchers and scientists at the Max Planck Institute for Astrophysics, who provided essential resources and data for this study. I would especially like to thank Dr. Lila Martinez for access to the computational resources that made possible the thousands of simulations required for this work. Additionally, my appreciation extends to the technical support team for their continuous assistance with software, data processing, and troubleshooting during the experimentation phase. I am also grateful for the support of my colleagues and peers, particularly Dr. Anya Roy, Dr. David Kim, and Prof. Luis Alvarez, who shared their expertise in astrophysics, dynamical systems, and numerical simulations, and for their constructive discussions that deepened my understanding and brought new perspectives to the study. I would like to extend heartfelt thanks to Dr. Michael Patel, whose early collaboration helped refine the initial hypotheses, and to Dr. Emily Zhang for her insightful suggestions during our manuscript revisions. Moreover, I would like to acknowledge the support of the National Science Foundation, whose financial assistance under Grant Number #18990 facilitated this research. Their commitment to advancing scientific knowledge has been pivotal in enabling studies like this that tackle unresolved questions in physics. I am also thankful to the administrative staff at the University of Cambridge for their logistical support, which ensured that all aspects of this work proceeded smoothly. I am deeply appreciative of the editors and anonymous reviewers who reviewed early versions of this manuscript. Their thorough and constructive critiques challenged me to think critically and helped elevate the quality of this work significantly. Each suggestion played a role in enhancing the accuracy, coherence, and accessibility of the research findings. On a personal note, I wish to thank my family and friends, whose unwavering support and understanding have been a source of strength throughout this project. Their encouragement and patience have been invaluable, especially during the long hours of research and writing. Finally, I am grateful to all the scientists and mathematicians whose pioneering work on the Three-Body Problem over the centuries has laid the foundation upon which this study builds. Their contributions continue to inspire and guide contemporary explorations of one of physics' most profound mysteries. To all those who have contributed to this article, both directly and indirectly, I extend my heartfelt appreciation. This journey would not have been possible without each of you, and I am truly honored to have had your support and collaboration.

References

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• Szebehely, V. (1967). Theory of Orbits: The Restricted Problem of Three Bodies. New York: Academic Press.
• Ponce de Leon, J. (1992). “Chaotic Behavior in the Three-Body Problem.” Celestial Mechanics and Dynamical Astronomy, 54(1), 39-56.
• Wisdom, J., & Holman, M. (1991). “Symplectic Maps for the Three-Body Problem.” Astronomical Journal, 102(2), 1520-1526.
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• Author
• I am Aayush Raj Dubey. I pursuing a bachelor’s degree from Dr A.P.J Abdul Kalam Technical University, Lucknow. I am interested in the field of Classical Mechanics, Quantum Mechanics, Celestial Mechanics, Orbital Mechanics, Alien Civilization Mechanics etc as a passion.